Electric hoist



25, 19.42. c. BRQNGERSMA ELECTRIC HOLST Filed .-sept. 6, 193s 2 Sheets-Sheet l d @ronge [-v was? 2 -wf d! :52 3 Zia/ r Aug. 2 5, 1942. c. BRoNGERsMA ELEcTRIc HoIsT Filed sept. s, V19323 2 Sheets-Sheet 2 l Colne/MAS* Y @f-,

Patented Aug. 25, 1942 ELECTRIC HOIST Cornelius Brongersma, Muskegon Heights, Mich., assignor to Manning; Maxwell & Moore, Inc., Y Muskegon, Mich., a corporation of New Jersey Application September 6, 1938, Serial No. 228,513

1 0 Claims.

The invention relates to electric hoists, and more particularly to hoists embodying a reversible electric driving motor.

In the copending application of Preston Whitcomb, Serial No. 228,509, illed September 6, 1938, an electric hoist is disclosed embodying a single phase alternating current motor of the starting controller actuating mechanism by virtue of which a relatively long period of dwell is obtained when shifting the hoist controller from lowering to hoisting position or vice versa. During this period of dwell, the brake on the hoist is automatically set so that it slows down the driving y m'otorto such a point that the speed lresponsive switch, which contolthe' motor starting winding. yis actuated thereby cutting the starting windihg'into'cir'cuit. This action is particularly important in viewA of. the' fact that it is an inherent characteristic of single phase alternating current starting winding motors that they can only be reversedcircuit. l

` Another object of the invention-is to provide in an electric hoistan improved' form of actuating mechanism whichjnot'only serves to insure when tnestarung winding is in a relatively lng'period of dwell when shifting the hoist controller fromlowering to hoisting position, or vice versa, but-which also cooperates with the hoist line so as 'to act as an Aautomatic limit control for stopping the hoist motor when the hoistv line reaches either of its extremities of movement.

The invention also resides in various structural improvements and combinations ,of elements ini the controller actuating mechanism by means of which a positive snap action of the controller is obtained.

Further objects and advantages oi the invention will become apparent as the following description proceeds taken in connection with the accompanying drawings, in which:

Figure v1 is :general perspective vievroiF-"anl electric hoist embodying the invention.

Fis42is an enlarged transverse sectional view of the hoist shown in Fig. 1, illustrating particul larly the hoist control and brake mechanism with the associated parts shown in dot-dash lines.

Fig. 3 is a wiring diagram of the motor control circuits for the hoist oi' Fig. l.

Fig. 4 is an enlarged vertical longitudinal sectional view of the hoist of Fig. l, illustrating particularly 'the controller and brake actuating mechanism with the associated general parts of the hoist indicated in dot-dash lines.

The particular hoist to which the invention is applied herein (Fig. l) embodies as its principal elements a reversible electric driving motor ill, a revolvable hoisting member in the form of a chain pinion ii (Fig. 4) and which is connected in driven relation with the motor through a speed reduction gearing contained within a gear case l2. The hoisting pinion Il is journaled within a housing I3 (Fig. 1) formed as an integral extension' on the inner face of the gear case i2 4directly below the motor I0, while the motor itself is bolted to an integral cylindrical extension I4 on the gear case. The hoist unit is supported by a suitable hook I5, which is attached to the upper I side of Vthe gear case extension il, and disposed substantially in vertical alinement with the hoisting pinion il. A hoist line, shown in the form of a roller-type chain ll, is reeved over the pinion Il and has one end secured to the gear case extension I l by a suitable tension spring Hb. A load hook I| is secured to the other end vof the chain. A brake mechanism, designated generally by the numeral I6, is provided for holding the motor lll4 and chain pinion Ii against rotation vwhenever the motor is stopped. This brake mechanism may, for the sake of compactness, be

housed within the cylindrical gear case extension Il (Fig. 4). It should be understood that the general arrangement of the hoist parts described above and their particular form constitutes no part of the present invention. The particular arrangement of parts described above is in fact disclosed and claimed in the copending application of Christopher H. Schramm, Serial No. 228,511, tiled September 6, 1938.

'I'he improved form of controller actuator mechanism herein contemplated is vparticularly adapted for 'use in hoists embodying an electric driving motor of the single phase alternating current starting winding type. The motor Il has been shown (Fig. 3) as being of this general type and is of a form commonly designated as a "split phase motor. It embodies a main winding l1 and an auxiliary starting winding i8. In

'order to make the motor as low in cost as possible. the starting winding Il is designed to have a low current carrying capacity, and accordingly must be cut out of circuit after the motor has ventional centrifugal type ordinarily supplied in such motors, and -in general is arranged to open, and thereby deenergize, the starting winding I8 as soon as the motor I accelerates to a speed of predetermined value.

deceleration period, although sometimes at a somewhat lower speed than thatat which it opens due to the inherent sluggishness 'of such switches. Y

Itis a characteristic of starting winding motors like that described above that they can only be reversed when the starting Winding is in circuit. In other words, if the motor 'I0 is operating, at normal speed in one direction, and hence with the starting winding- I8 deenergized, a mere reversal in the instantaneous polarity of the voltage applied to the main winding II will not serve to reverse the motor but will, on the other hand,

serve to continue it in rotation in the same direction. This action is to be distinguished from that obtained in more expensive types of reversible motors in which a simple reversal of the instantaneous polarity of the voltage applied to During stoppage of the motor, the switch I9 will again close during theA the motor will cause it to reverse.` In common'l electrical engineering parlance, the motor I0 illustrated herein cannot be plugged Consequently, in order that the motor IIJ may be reversed so as to change from hoisting to lowering or vice versa, it is necessary that the reversal operation include an energization of the starting winding I8. In general, the improved actuating mechanism herein disclosed is of such character that there will be a relatively long period of dwell between the time that the motor connections are set up for one direction of rotation the instant at which they are reversely connected. During this period of dwell, the motor is deenergized and the brake mechanism yII applied so that the motor is slowed down to a point at which the speed responsive switch I9 recloses, thereby cutting the starting winding I8 back into circuit. .By providing a relatively long period of dwell, as distinguished from an almost instantaneous change-over, a sufficient slowing down of the motor is insured to accomplish the necessary closure of the speed responsive switch In the illustrative construction, areversing 'I'he contact arrangement for the reversing controller 20 is shown in developed or schematic form in Fig. 3. It includes two rows of fixed contacts 24-26 and'ZI-29 as well as movable contacts 30 35. The movable contacts are shifted by the rock shaft 22. When .the rock shaft is in its neutral position, the center line of the movable contacts occupies the position indicated by the dot-dash lineN in Fig. 3, and similarly when the rock shaft is in its hoisting and lowering positions the center line of the set of movable contacts occupies respectively the positions indicated by the dot-dash lines H and L. Single phase alternating current is supplied to the motor I0 through the controller 2liV from supply lines L1 and L2. In the operation ofthe device when the controller 20 is shifted to its hoistingv position, the main winding I'I of the motor isl energized (through a circuit L1 36 24 '3I same time the starting winding I8 is energized (through a. circuit L1-36- 24-3I-40--32-2'I- 4I IB I9 42 26 34' 43 35 29 39 La). Since the speed responsive switch I9 is included in the circuit of the starting winding I8, this winding will be deenergized as soon as themotor comes up to speed and opens the switch I9. Similarly, when the controller 20 is shifted to its lowering position, the motor mainl winding I 'I` is energized, although in a reverse sense as compared to that for hoisting (through a circuit L1- 36 24 30 40 3'I 28 38 I1 31 25 33 43 34 29 39 L2), while the starting winding I8 is energized in the same .sense as before sive switch I 9 is included in the startingwindnism may be of any suitable form and has been shownherein as being ofthe mechanical type.

controller 20 (Fig. 4) isvprovided which is of conventional construction and is secured to the lower side of the motor I0 by a bracket 2|. This `controller includes a rock shaft 22 carrying a cross arm 23 on its outer end. When the rock shaft 22 is in the position illustrated in Fig. 2,

and with the cross arm 23 horizontal as indicated by the dot-dash line N, the controller is inits neutral position andthe motor I0 is opencirculted. When the rock shaft-22 is oscillated in a clockwise direction (as viewed in Fig, 2) so that the cross arm 23 occupies the angular position indicated by the dot-dash line L, the motor I0 is energized vfor lowering. Similarly wli'en the rock shaft 22 is oscillated in the opposite or counterclockwise direction, until the cross Varm 23 occupies the angular position indicated by the dot-dash line H, the motor is energized for hoisting the usual centering springl (not shown) included in the controller 20, restores the rock shaft 22 to its neutral position when the pull on the cross arm 23 is released.

The particularl brake illustrated includes a brake `drum 44 fast 'on shaft 45 of the motor I0 (Fig. 2) .v This brake drum is embraced by two cooperating brake shoes gear case I2 by pins'4'l. The brake shoes 46 are normally urged into frictional engagement with the brake drum 44 by apair of helical 'compression springs 48 surrounding a transverse shaft-49, which is journaled` in the housing I4.

Cam -followerextensions 50, integral with the brake shoes 46, are loosely slidable on this shaft 49 and the springs 48 are interposed between vthe outer faces of these cam followers and the opposed faces of lugs 5I formed on the housing I4. 'I'he cam followers 50 are provided with V-shaped notches Iin their inner faces which receive a generally diamond-shaped cam 52 that is fixed to the shaft 49 by a pin 53. Consequently, -when the shaft 49 is oscillated inxeither a clockwise or a.

"brake I6 to be set when counterclockwise direction from the position shown in Fig. 2, the cam 52 will push the cam followers 50 apart therebyreleasing the brake In general,

controller is so arranged neutral position' and released whenever the con- 46 pivoted on the inner side of the troller is moved to either hoisting or lowering position.

In the particular construction illustrated (Figs.

2 and 4), the improved actuating mechanism forthe controller 20 and brake I8 embodies a pair of generally horizontal yoke-shaped levers 54 and 55. These levers are pivoted on the inner face of the gear case l2 as indicated at 56 (Fig. 4) and are connected to the opposite lends of the cross arm 23, which is fast on the controller rock shaft or control member 22. This connection to the cross arm 23 is preferably formed by a pair of vertically movable pins 51 and 58 plvoted on the outer ends of the levers 54-55 and having a lost motion connection with the cross arm 23. 'I'he pins 51-58 extend through complemental holes in the outer ends of the cross arm and engage the same by means of abutments in the form of nuts 5ll and 58 threaded thereon. By adjusting the position of the nuts 51e- 58a on the pins 51-58, the distance can be adjusted through which the levers 54-55 must be moved before a corresponding movement of the cross arm 23 results.

Manual operation of the controller actuating mechanism isaccomplished by means of a pair of vertically movable pull cords 59 and 60 (Fig. l). These `pull cords are respectively secured to the lower ends of vertically movable plungers 6| and 52 which are slidably mounted in. vertical transverse bores 6I* and 62* fastened in the outer ends of the levers 54-55 (Fig. 2). Yieldable connections are formed between the plungers 6|62 and their respective levers 54-55 by helical compression springs 63 and 54. These compression springs are interposed between the upper faces of the levers 54-55 and enlarged heads 55 and i5 fashioned on the plungers 6I-62.

The actuating levers 54-55 are yieldably retained in their horizontal or neutral positions by cooperating latches 61 and 68 having their outer faces notched at 6l* and 68* to receive the corresponding levers. The latches are mounted for swinging movement toward and away from the levers 54-55 on pivots 59 and are yieldably urged into engagement with their associated levers by means of a helical compression spring interposed between the adjacent faces of the latches and surrounding lugs 1I and 12 thereon. By arranging the latches 61--58 with the lugs 'll-12 thereon in such close proximity, simultaneous release of the latches from their associated levers 54-55 is prevented. This interlocking of the latches makes necessary the sequential movement of the levers 54-55 and introduces a substantial cperiod of time delay between their successive operations.

The latches 81-88 cooperate with the actuator plungers GI-SZ and their associated con-v necting springs 6364 in such manner that the levers 54-5-55 andi consequently the controller r-ock shaft :22 are 'moved with a rapid snap action. To this end, cam surfaces .Glb and i8" are formed on the outer faces of thelatches to coyoperate with complemental cam surfaces 55' and i5' ony the plunger heads 65-66. When the operator pulls down lon the cord 59, for lowering of the load hook H, the spring 63 is compressed by the downward movement of the plunger 6I and the latch 61 is finally cammed out of engagement with the lever 54 by the plunger head 65. When the latch d isengages the lever 54, the

lstoredup energy in thespring 53 causes the lever to snapdownward; thereby quickly shiftlng the rock shaft 22 in a clockwise direction to its lowering position. Similarly, when the operator pulls down on the control cord 60, the

nism for the motor controller also serves to control the brake I6. For this purpose, a lever 13 fast on the brake actuator shaft 49 is pivotally connected through an intermediate link 14 with the upright arm 15 of a bell crank lever, which is loosely journaled on the pivot pin 56 of the levers 54-55. The second arm 16 of the bell crank is disposed transversely beneath the levers 54-55. When these levers 54-55 are in their neutral or horizontal position, the bell crank I5- 15 is urged in a clockwise direction (as viewed in Fig. 4) by a helical compression spring 11. In such case, the brake actuating linkage occupies the position shown in full lines in Fig. 4 and the brake is set. Upon downward movement of either of the levers 54 or 55, the

- bell crank 15-16 is oscillated in a counterclock- I general, be clear from the foregoing description.

As a brief rsum, however, it should be noted first of all that when the actuator parts are in the positions illustrated in Figs. 2 and 4, the controller is in its neutral position so that the motor `I|l is deenergized, and, furthermore, the brake I6 is set so that if a load is applied to the hook |I, there will be no inadvertent descent of the hook due to gravity. If the operator wishes to initiate a hoisting movement of the load hook IIC, he pulls down on the controlcord 50. This causes the controller rock shaft to be moved to its hoisting positionwith asnap action as was previously described, and at the same time releases the brake I6. Such movement of the controller energizes the motor lll for hoisting through the circuits noted. The operator keeps the cord 60 pulled down so long as he wishes the hoisting movement to continue. At completion of the desired amount of hoisting movement, he simply releases the cord 60 and the actuator lever 55 is pushed back to its initial or neutral position bythe spring ll, which biases the bell crank 15-16. The lever 55 thus releases the cross arm 23 so that the centering spring in the controller 20 is freed to return the controller rock shaft 22 to neutral. Similarly, the operator pulls down on the cord 59 to initiate a lowering movement of the load hook I l Such downward movement of this control cord causes the controller 20 to be snapped to its lowering position and so releases the brake I6. Again, the control cord is held down until the desired amount of 1 lowering movement is completed and then the hoist is stopped by simply releasing the pull cord which the brake I6 is set, because of the mutual" interference of the latches 61-68. During this period of dwell,A thebrake I6 quickly decelerates the motor I to a point at which the speed responsive switch I9 closes; By virtue of this closure of the speed responsive switch, the motor starting winding I8 is cut into circuit so that the subsequent reversal of theinstantaneous polarity of the voltage applied to the motor will cause it to rotate in the opposite direction The provision of a snap acting type of mechanism also aids in lengthening the period of dwell during which the brake is set, since an appreciable period of time is consumed in storing up the necessary force in the spring 63 `or 64 to accomplish the release of their associated levers 54-55. The use of a snap acting type of mechanism has a further advantage in that it prevents either an inadvertent or deliberate attempt on the part of the operator to move the controller 2-0 slowly to either its hoisting -or lowering positions. This latter type of operation is particularly undesirable since it is likely to result in an appreciable in-l terval of time between the release of the loadholding brake and the energization of the motor.

the hoist without the necessity of providing any additional parts. The shock of engagement of the chain IIa with the levers 54-55 is cushioned respectively by the springs IIb and 19. This shock cushioning arrangement is, however, not my invention but is described and claimed in the Whtcomb et al. application noted above.

Although a particular embodiment of the invention has been shown and described in some detail, there is no intention to thereby limit the invention to such embodiment, but on the other hand, the appended claims are intended to cover all modifications and alternative constructions within the spirit and scope of the invention.

I claim as my invention:

1. An electric hoist comprising, in combination, a revolvable hoist member having a hoisting line reeved thereover for hoisting and lowering movement upon rotation of said hoist member in opposite directions, a single phase alternating current electric motor connected in driving relation with said hoisting member, said motor embodying a main' winding and an auxiliary starting winding and being capable of reversal only when said starting winding is energized, means including a speedresponsive switch for deenergizing said starting winding when said motor is rotating at a speed in excess of a prede- If there is any such. interval, a load attached to the hook I Ic will fall rapidly due to the gravity and thereby quickly accelerate the motor Ill/to a. dangerous speed. Such acceleration of the motor by a freely falling load is likely to break the centrifugal switch I9 or the motor rotor. Even if the switch I9 is not broken, it is likely to be opened,`and with the motor starting winding I 8 thereby open circuited, any subsequent energization of the main winding will simply cause the motor to continue rotation in the lowering direction no matter what the setting of the con.

troller contacts may be. Such a snap actingtype of actuator, as is herein provided, effectively preventsA this dangerous type of operation.

The levers 54 and 55 are preferably arranged not only to form a part of the regular actuating mechanism but also to serve as limit control devices at the respective extremities of movement for the hoisting chain IIa. pose, the lever 54 is positioned at one side'of the hoisting pinion II and within the loop formed in the upper end of the chain IIS, while the lever' 55 is positioned on the opposite side of the hoisting pinion and in alinement with an abutment on the lower end of the chain IIa. This abutment has been shown in the form of a collar 18 (Fig. 1) yieldably connected to the chain and hook I I c by a compression spring 19. During the lowering operation, the lever 54 is of course held in its downwardly tiltedposition. At the extremity of the lowering movement of the chain II, the loop in the chain which embraces the lever 54 engages this lever and pulls it back to its horizontal or neutral position, thereby eiec- Itively stopping'th'e hoist. Similarly, during the hoisting operation, the other lever 55'is tilted `downwardly and at the corresponding extremity of hoisting movement for 'the chain I I the abutment I8 engages the lever 55 and swings it`upward to its neutral or horizontal position, there- ,by again stopping the hoist. With this arrangement, an effective limit control is provided for For this latter purtermined value, 'a reversing controller for said motor embodying a control member oscillatable from a central neutral position in which said motor is deenergized alternatively to hoisting and lowering positions in which said motor is connected to a supply line in respectively reversed senses, means-including abrake for releasably holding said motor against rotation, 'means responsive to the movement of said control member for releasing said brake only when said conl trol member is in its hoisting and lowering positions, means including a pair-of actuator members operatively connected to said control member for respectively moving the same to hoisting and lowering position, and time delay means includingtwo latches engageable with said actuator members for delaying the movement of said control member from hoisting position to lowering position or vice versa, whereby said brake is applied during the resultant period of dwell to slow down said motor for actuation of said speed same to hoisting and lowering positions, and

means including a pair of separate latches yieldably engaging respective ones of said actuator members for causing said actuator members to move with a rapid snap action upon the application of a predetermined force to said actuator members.

3. An actuator mechanism for a reversing controller of an electric hoist of the type embodying an electric motor reversible only when its speed is reduced to a predetermined value by an associated brake which is automatically set when its axis of oscillation, means pivotally supporting A said levers at the inner ends thereof for swinging movement in parallel planes on opposite sides of said axis, a pair of latches disposed back to back an electric motor reversible only when its speed is reduced to a predetermined value by an associated brake which is automatically set when the controller is in neutral position and released whenever the controller is shifted to hoisting or lowering position, comprising in combination, a reversing controller member oscillatable from a neutral position alternatively to hoisting and lowering positions, means including a pair of acbetween said levers, means yieldably urging said l latches into engagement with the respective levers, means for moving said latches out of engagement with their associated levers upon the application of a predetermined force to said levers, and means including engageable parts on said latches for preventing simultaneous disengagement thereof from their associated levers.

4. An actuator mechanism for a reversing controller of an electric hoist of the type embodying an electric motor reversible only when its speed is reduced to a predetermined value by an associated brake which is automatically set when the controller is in neutral position and released whenever the controller is shifted to hoisting or lowering position, comprising in combination, a

i reversing controller member oscillatable from a neutral position alternatively to hoisting and lowering positions, two levers disposed side by side and having the outer ends thereof connected to said controller member on opposite sides of its axis of oscillation, means pivotally supporting said levers at the inner ends thereof for movement in parallel planes on opposite sides of said axis, 'each of said levers having a' transverse aperture therein adjacent its outer end and lying in the plane of movement of the respective lever, a plunger slidable in each of said apertures, each of said plungers having an enlarged head thereon, a helical compression spring surrounding each of said plungers and interposed between the head thereon and the associated lever to form' a yieldable resilient connection therebetween,

separate pivoted latches disposed back to back between said levers, means yieldably urging said latches into engagement with the respective le- `vers, and means including cooperating cam surfaces on said latches and plunger heads for alternatively moving said latches out of engagement with their respective levers in response to predetermined movement of the associated\ plunger toward its corresponding lever.

5. An actuator mechanism for a reversing controller of an electric hoist of the type embodying an'electric motor reversible only when its speed is reduced to a predetermined value by an associvated brake which is automatically set when the controller is in neutral position and released whenever'the controller is shifted to hoisting or lowering position, comprising in combination, a reversing controller member oscillatable from a neutral position alternatively to hoisting and lowering positions, means including a pair of actuator members `operatively connected toj said controller for respectively moving the same to hoisting and to lowering positions, means including a pair of latches yieldably engaging respective ones of said actuator members forreleasably holding the same against movement, and means for preventing simultaneous disengagement of said latches.

6. An actuator mechanism for a reversing controller of' an electric hoist of the type embodying `for causing a time delay interval between sequential actuations of said actuator members, the lastv mentioned means including a plurality of elements interconnecting said members and interlocked with each other to compel sequential movement of such elements between sequential actuations of said members and thereby introduce said period of time delay.

7. An actuator mechanism for a reversing controller of an electric hoist of the type embodying an electric motor reversible only when its speed is reduced to a predetermined value by an associated brake which is automatically set when the controller is in neutral position and released whenever the controller is shifted to hoisting or lowering position, comprising in combination, a reversing controller member oscillatable from a neutral position alternatively to hoisting and lowering positions, means including a pair of actuator members operatively connected to said controller for respectively moving the same to hoisting and lowering positions, and means operatively connected with said actuator members and operable in response only to the application to said members of a force exceeding 'a predetermined value for causing said actuator members to move with a rapid snap action.

8. An electric hoist comprising, in combination, a hoist unit including a revolvable hoisting member and an electric driving motor connected thereto, a hoist line reeved over said hoisting member, means securing one end of said hoist line to said unit with a loop depending between said one end and said hoisting member, load supporting means secured to the other end of said hoist line, arr abutment on said hoist line adjacent said last named means, a reversing controller for said motor mounted on said holst unit and including a control member oscillatable from a central neutral position alternatively to hoisting and lowering positions, a pair of structurally separate generally horizontal levers pivoted for individual movement on said hoist unit on opposite sides of said hoisting member and each having a lost motion connection with said'control member on opposite sides of the axis of the oscillation thereof, and manually operable means attached to said pivoted levers for alternatively swinging one or thev other of the same downward from its horizontal position to oscillate said control member from its neutral position to its corresponding hoisting or lowering position, one of said levers being disposed within said hoist line loop for engagement thereby at the extremity of lowering movement =of said hoisting line `and the other of said levers being disposed for engagement by said abutment at the extremity of hoisting movement of said hoist line.

9. An electric hoist comprising, in combination, a hoist unit including a revolvable hoisting mem- -ber and an electric driving motor connected oneof 'saidcontrol Said ht--lin member, means securing one end of said hoist line to said unit with a loop depending between said one end and said vhoisting member, load supporting means secured to the other end oi said hoist line, an abutment on said hoist line adjacent said last vnamed means, a reversing controller for said motor mounted on said hoist u nit and including a controller member oscillatable from a 'central' neutral position alternatively to hoisting and lowerin'g'positions, a pair of strucbodying an electricmotor 1 ment of said hoist. linerv trol members being disposed for vengagement by e v said abutment at the extremity of hoisting :move- 10i An actuator mechanism for ai controller of an electric hoist of the typel ein-v o its speed is reducedl to a predetermined value by turally separate: control members mounted l-i'or generally vertical-individual movement .on-said`v I hoist uniton oppositesides of said hoisting mein-l -ber 4and Aeachjhavi'ng a lost motion connection with said osclllatable controller. member-on 'opi5- ,1 posite sides 'of the axis of the oscillation thereof,A

and manually operable means cooperating wit'lrl said vertically movable control members for al-J ternauveiy shifting one-0r me other' yor the' samev -v downward fromV its -idle positionto'osclll'a'te Said controller meinberlinm its neutral` positiongto o its corresponding'hoistlng-or lowerlng'posltinn, members :disposed 1001` for engagements. f a

bination, 'ai latable fromga. neutral hoistingand lwerins -an .associated vbrake which isaut'omatically set y when thecontroller is in neutral position".andV released :whenever the `controller-"j ils .tof 'l yhoisting-;onloxyv'erin'gposition,cormirlsing inlcomreverslngvcontrcllerfpock.tshart'oscilf-. jf vpitionfalternatively.' to n positions,manually.ober-'-\-` 'able actuating nieans'tor said' rocksbatt,'includ'-v mgi'shatteodajpaip of, nnctedmspetive-v- Vnosite tends (of, said' 'crossi arm for.. moving", Isaiding a crossjarm onithepull cordsoperatively co ther-emrv at lthe extremity 'of 'idwermg movement r of said hoisting, and-j 'meting-:Q1 Isaid` cone reversing A reversible onlvwhen v 

